Aspects of this disclosure are generally related to data storage systems that can be used to maintain relatively large data sets and support a relatively large number of concurrent users. The basic building blocks of the data storage systems may include storage engines or storage servers. A plurality of storage engines or storage servers can be interconnected in order to function together as a storage array or storage server cluster. Each storage array or storage server cluster typically includes multiple physical storage devices that are used to present logical storage devices to instances of applications running on host devices.